Honeywell Burner control unit S4560B1055U

The Honeywell S4560B1055U is a burner control unit for atmospheric gas burners, compliant with EN 298. It operates at 220–240 V with a safety time of 50 seconds and no pre-purge. The unit uses ionization flame detection and features a non-volatile lockout. It connects via a Molex 3001 multi-edge connector and is rated IP40. This control box is designed for use in Protherm Grizzly 65...150 KLO-12 boilers.

When selecting a replacement burner control unit, ensure the supply voltage, safety time, and flame detection method match the original. The connector type and pin configuration must be compatible with the existing wiring. Verify the protection class and mounting dimensions to fit the boiler's enclosure. For this type, the gas valve voltage and current ratings must also align with the system's requirements.

Common failures include lockout without ignition, which may indicate a faulty flame sensor or wiring issue. If the unit repeatedly attempts ignition but fails, check the ionization electrode and cable connections. A non-responsive unit could be due to a blown internal fuse or a defective transformer. In case of intermittent operation, inspect the Molex connector for loose contacts or corrosion.